物理化学学报 >> 2011, Vol. 27 >> Issue (07): 1666-1672.doi: 10.3866/PKU.WHXB20110715

电化学和新能源 上一篇    下一篇

锂离子电池用Cr2O3/TiO2复合材料的电化学性能

赵星, 庄全超, 邱祥云, 徐守冬, 史月丽, 崔永丽   

  1. 中国矿业大学材料科学与工程学院锂离子电池实验室, 江苏 徐州 221116
  • 收稿日期:2011-02-24 修回日期:2011-03-30 发布日期:2011-06-28
  • 通讯作者: 庄全超 E-mail:zhuangquanchao@126.com
  • 基金资助:

    中央高校基本科研业务费专项资金(2010LKHX03、2010QNB04、2010QNB05)和中国矿业大学科技攀登计划(ON090237)资助项目

Electrochemical Performance of Cr2O3/TiO2 Composite Material for Lithium Ion Batteries

ZHAO Xing, ZHUANG Quan-Chao, QIU Xiang-Yun, XU Shou-Dong, SHI Yue-Li, CUI Yong-Li   

  1. Li-ion Batteries Laboratory, School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116, Jiangsu Province, P. R. China
  • Received:2011-02-24 Revised:2011-03-30 Published:2011-06-28
  • Contact: ZHUANG Quan-Chao E-mail:zhuangquanchao@126.com
  • Supported by:

    The project was supported by the Fundamental Research Funds for the Central Universities, China (2010LKHX03, 2010QNB04, 2010QNB05) and Science and Technology “Climbing” Program of China University of Mining and Technology (ON090237).

摘要:

采用高温固相反应法合成了Cr2O3/TiO2复合材料, 运用X射线衍射(XRD)、扫描电子显微镜(SEM)、充放电测试、循环伏安(CV)、电化学阻抗谱(EIS)等对其结构、形貌和电化学性能进行了表征. 研究结果表明: TiO2掺杂能够显著改善Cr2O3的充放电循环性能, Cr2O3/TiO2复合材料在充放电循环22周后仍有454 mAh·g-1的可逆循环容量, 容量保持率达到了73.6%, 主要归因于TiO2掺杂能够显著提高Cr2O3的电导率. Cr2O3/TiO2复合材料首次放电过程中由于电极体积膨胀导致的固体电解质相界面(SEI)膜迅速增厚和活性材料电导率的降低可能是其首次充放电过程中存在较大不可逆容量和循环容量衰减的重要原因.

关键词: 锂离子电池, Cr2O3/TiO2复合材料, 转化反应, 电导率, 固体电解质相界面膜

Abstract:

The Cr2O3/TiO2 composite material was prepared by a high-temperature solid-state reaction and its structure, morphology, and electrochemical performance were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), charge-discharge test, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). We found that TiO2 doping significantly improved the cyclic performance of Cr2O3 and the reversible capacity of the Cr2O3/TiO2 composite material was 454 mAh·g-1 after 22 charge-discharge cycles, therefore, it has a capacity retention of 73.6% and this is mainly due to TiO2 doping that significantly increases the conductivity of Cr2O3. Our results revealed that the initial large irreversible capacity and the capacity fading could be attributed to an increase in the thickness of the solid electrolyte interface (SEI) film and a reduction in the conductivity of the materials. This was caused by a volume expansion of the Cr2O3/TiO2 electrode during the first discharge process.

Key words: Lithium ion battery, Cr2O3/TiO2 composite material, Conversion reaction, Conductivity, Solid electrolyte interface film

MSC2000: 

  • O646